Characterization of human triosephosphate isomerase S-nitrosylation.
Romero, J.M., Carrizo, M.E., Curtino, J.A.(2018) Nitric Oxide 77: 26-34
- PubMed: 29678765 
- DOI: https://doi.org/10.1016/j.niox.2018.04.004
- Primary Citation of Related Structures:  
6D43 - PubMed Abstract: 
Triosephosphate isomerase (TPI), the glycolytic enzyme that catalyzes the isomerization of dihydroxyacetone phosphate (DHAP) to glyceraldehyde-3-phosphate (G3P), has been frequently identified as a target of S-nitrosylation by proteomic studies. However, the effect of S-nitrosylation on its activity has only been explored in plants and algae. Here, we describe the in vitro S-nitrosylation of human TPI (hTPI), and the effect of the modification on its enzymatic parameters. NO-incorporation into the enzyme cysteine residues occurred by a time-dependent S-transnitrosylation from both, S-nitrosocysteine (CySNO) and S-nitrosoglutathione (GSNO), with CySNO being the more efficient NO-donor. Both X-ray crystal structure and mass spectrometry analyses showed that only Cys217 was S-nitrosylated. hTPI S-nitrosylation produced a 30% inhibition of the Vmax of the DHAP conversion to G3P, without affecting the Km for DHAP. This is the first study describing features of human TPI S-nitrosylation.
Organizational Affiliation: 
Centro de Investigaciones en Química Biológica de Córdoba (CIQUIBIC, Universidad Nacional de Córdoba - Consejo Nacional de Investigaciones Científicas y Técnicas (UNC-CONICET)), Departamento de Química Biológica Ranwel Caputto, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, X5000HUA, Córdoba, Argentina. Electronic address: jromero@fcq.unc.edu.ar.